Trainer Michael Bell has spoken of his "distress" at the images on the front page of Saturday's Daily Mirror which show his stable star Wigmore Hall being euthanized.
The seven-year-old broke a leg at Doncaster last week and the newspaper obtained images of the gelding being put down.
Bell was full of praise for the treatment Wigmore Hall received on Town Moor and was upset by what he described as an "insensitive" piece.
"It's a very insensitive thing to publish," said Newmarket-based Bell.
"The first thing I picked up on was that the journalist referred to Wigmore Hall as 'it' and that sums up his lack of understanding of the situation.
"The love we have for horses, people who work with them day in and day out, no one ever calls a horse 'it'.
"Those of us who work in the industry love them the most, you only need to go into any yard to see that, they are loved and adored.
"The vets did an astounding job, they were on the scene in 30 seconds and they have to make an instant decision, sometimes it is better for them to deal with it quickly than let the horse suffer. The most important thing is the welfare of the horse.
"Everyone has a mobile phone with a camera on it these days and that appears to be where the photos have come from.
"I just don't see the plus side of printing them, it is very distressing for us. After losing one of our favourites we then have to go through this.
"From my point of view the journalist just shows his lack of understanding of horses throughout the piece."
The British Horseracing Authority defended racing's welfare record after seeing the images.
Jenny Hall, chief veterinary officer for the British Horseracing Authority, said: "The first priority in British racing is always the welfare of its competitors, both human and equine.
"The team of veterinary surgeons were at Wigmore Hall's side in moments after the injury. The vets were able to make an immediate assessment of Wigmore Hall's condition and in this case the diagnosis was made that the injury was untreatable and so the correct course of action for Wigmore Hall's welfare was for him to be humanely put down.
"The highest standards of horse welfare are demanded of all jockeys, trainers and racecourses and none of the 1,450 fixtures held annually in Britain can take place unless key equine welfare criteria have been satisfied. British racing's welfare standards far exceed existing animal welfare legislation.
"Over the last 15 years, the equine fatality rate in British Racing has fallen by one-third, from just over 0.3 per cent to just over 0.2 per cent of runners."
Dr. Peter Webbon, former chief executive of the Animal Health Trust, said: "When it comes to horse welfare, British racing has a track record to be proud of and British racing is among the world's best regulated animal activities.
"The BHA is the Government recognised body responsible for the regulation of horseracing and together with the RSPCA and World Horse Welfare, it is a leading signatory of the National Equine Welfare Protocol.
"Racehorses in Britain are among the healthiest and best looked after two per cent of horses in the country. The sport employs over 6,000 people to provide first-class care and attention for the 14,000 horses in training, providing them with a level of care and a quality of life that is virtually unsurpassed by any other domesticated animal."
The BHA said it is seeking an immediate meeting with the editor of the Daily Mirror over the use of the images in the article.